In conventional motion picture film movement in both cameras and projectors, successive frames of the film are moved into registration with the film gate aperture and held in position for a given dwell period during which exposure or projection of the film takes place. After the dwell period, the film is transported, either by intermittently operated "pull down" claws or intermittently operated sprocket wheels provided with sprocket teeth. In some systems, captive film loop arrangements are provided for continuous movement of the film from its pay-out reel to its take-up reel with the dwell periods being effected by movement of the captive loop rollers. An example of this latter arrangement is shown in my U.S. Pat. No. 3,613,978.
In all cameras and projectors in which intermittent film movement is involved, some type of pressure or aperture plate is necessary to hold the film steady during the dwell period. Examples of such mechanisms are shown in U.S. Pat. Nos. 1,308,443, 1,692,092, 3,612,674 and 3,914,035. However, none of these patents except 3,612,674 is concerned with relatively large film formats. With large film formats special problems such as flutter can develop as a consequence of the rapid acceleration and deceleration of the film in carrying out the intermittent movement in the film gate. In the case of U.S. Pat. No. 3,612,674 there are lacking registration pins which are essential for high quality reproduction.